Optimizing an mHealth Intervention to Change Food Purchasing Behaviors for Cancer Prevention: Protocol for a Pilot Randomized Controlled Trial

Background Dietary intake is a powerful modifiable factor that influences cancer risk; however, most US adults do not adhere to dietary guidelines for cancer prevention. One promising pathway for improving dietary adherence is targeting grocery shopping habits. Interventions might facilitate healthy grocery choices, with a combination of mHealth and traditional methods, by promoting the salience of dietary goals while shopping, enhancing motivation to make dietary changes, and increasing household support for healthy food purchasing. Objective This pilot study will assess feasibility and acceptability of intervention components designed to improve adherence to dietary guidelines for cancer prevention (preliminary aim). The primary aim of the study is to quantify the effect of each intervention component, individually and in combination, on dietary intake (primary aim) and grocery store food purchases (exploratory aim). Mediation analyses will be conducted to understand the mechanisms of action (goal salience, motivation, and household support—secondary aims). The overarching goal is to optimize an mHealth intervention to be tested in a future fully powered clinical trial. Methods The study enrolled adults (N=62) with low adherence to dietary recommendations for cancer prevention. In a 20-week program, all participants attend a nutrition education workshop and receive weekly educational messages through an app. A factorial design is used to test 4 intervention components: (1) location-triggered messages: educational messages are delivered when arriving at grocery stores; (2) reflections on the benefits of change: content is added to messages to encourage reflection on anticipated benefits of healthy eating, and participants attend an additional workshop session and 3 coach calls on this topic; (3) coach monitoring: food purchases are monitored digitally by a coach who sends personalized weekly app messages and conducts 3 coaching calls that focus on feedback about purchases; and (4) household support: another adult in the household receives messages designed to elicit support for healthy food purchasing, and support is addressed in 3 coach calls and an extra workshop session attended by the index participant and household member. Assessments are completed at weeks 0, 10, and 20 using self-report measures, as well as objective capture of grocery data from the point of purchase using store loyalty accounts. Results The National Cancer Institute funded this study (R21CA252933) on July 7, 2020. Participant recruitment began in the spring of 2021 and concluded with the successful enrollment of 62 participants. Data collection is expected to be completed in the summer of 2022, and results are expected to be disseminated in the summer of 2023. Conclusions The results of this study will inform the development of scalable interventions to lower cancer risk via changes in dietary intake. Trial Registration ClinicalTrials.gov NCT04947150; https://clinicaltrials.gov/ct2/show/NCT04947150 International Registered Report Identifier (IRRID) DERR1-10.2196/39669

Overall Impact: This R21 application proposes to test the feasibility of four intervention components in a factorial experimental design. Each intervention component is delivered via smartphone and targets a theoretical construct related to dietary change. The four interventions are: 1) location-triggered texts to promote goal salience upon entering grocery stores, 2) texts to promote reflection on the benefits of dietary change to increase motivation, 3) texts from a coach based on passive grocery data monitoring providing feedback on purchases to increase supportive accountability, and finally 4) texts to another member of the household to increase support for the participant's healthy food purchases. The investigative team and environment are very strong. However, multiple weaknesses limit the potential of this study for public health impact. The rigor of prior research on motivation and mhealth dietary intervention is under-developed. The motivation measure also does not appear to match the way motivation is operationalized in the intervention. The goal salience location-triggered texts and the objective passive data streaming from loyalty cards are both highly innovative and potentially impactful areas for research. Unfortunately, the other proposed intervention components are much less compelling due to the weak rationale and unclear theoretical framework provided. The anticipated impact of the proposed study is moderate.

Strengths
• The investigators make a compelling case that education is necessary but not sufficient to produce meaningful dietary change.
• Grocery store food purchases are an appropriate target for intervention.
• The rationale for targeting goal salience is strong, and the investigators have preliminary data demonstrating the feasibility of methods for targeting this construct.
• Mhealth methods are well-suited to address grocery store food purchasing behavior.

Weaknesses
• The theoretical framework is confusing. Too little specific information is provided on the theory underlying each of the included constructs. The discussion of the rigor of prior research into each of these constructs is underdeveloped.
• The discussion of motivation, in particular, is shallow and should be clarified. Most of the works cited do not appear to use a Self-Determination Theory framework, and it is not clear which subconstructs are being targeted specifically (Intrinsic motivation? Integrated regulation? Autonomous regulation overall?) The number of ACT interventions cited suggests that integrated regulation may be the most appropriate target, but this section as it is written does not provide sufficient rationale for the hypothesis that texts promoting reflection on benefits would increase a specific type of motivation which would then in turn impact eating behaviors. • The rigor of prior mhealth studies is also not sufficiently covered. No case is made for the hypothesis that two texts per week is an appropriate dose of intervention or that texts relating to benefits, accountability, or social influence from other household members impact mediators or behavior.

Strengths
• Dr. Butryn is an outstanding investigator and very well-qualified to lead the proposed research study.
• The Co-Investigators and consultants are highly qualified with appropriate scopes of work matched to their areas of expertise.

Strengths
• Just-in-time location-based texting represents a very promising innovation for targeting grocery shopping behavior.
• Objective assessments of purchasing behavior will occur via a novel passive stream from loyalty cards.
• Use of a factorial design for feasibility studies is relatively rare.

Weaknesses
• A lack of adequate, specific explanation of the four theoretical constructs being targeted makes it difficult to determine the contribution to the literature.

Strengths
• The factorial design will allow simultaneous pilot testing of the feasibility of four different intervention components.
• Procedures for randomization are rigorous.
• Sex will be included as a variable in the algorithm for randomization.
• One intervention is assigned to each arm with clear differences between the type of texts participants in that group will receive.
• Specific benchmarks for major variables are discussed.
• The plan for mediation analysis is rigorous.
• Missing data will be dealt with appropriately.
• A passive, objective measure of grocery shopping will be the primary outcome, with the ASA24 serving as a standard measure of dietary intake. • It appears that participants in the location triggered text group will receive less attention (shorter/less frequent texts) than participants in some of the other groups. This difference in attention may bias results.

Weaknesses
• The measure of motivation is from Self-Determination Theory and thus does not appear to match the way motivation is being operationalized in the intervention (e.g., referring to an amount of motivation, generally). It is not clear what types of motivation are the outcomes here an increase in autonomous, a decrease in controlled, etc.).
• Sex and several other variables are included in the randomization plan, but it is not clear whether they will be included in analyses as covariates.

Strengths
• The environment is excellent.

Strengths
• The timeline is very specific, with clear milestones.

Acceptable Risks and/or Adequate Protections
• Protections for human subjects are appropriate.

Data and Safety Monitoring Plan (Applicable for Clinical Trials Only):
Acceptable o A DSMB will be convened. The data and safety monitoring plan is adequate.

Inclusion Plans
• Sex/Gender: Distribution justified scientifically • Race/Ethnicity: Distribution justified scientifically • For NIH-Defined Phase III trials, Plans for valid design and analysis: Not applicable • Inclusion/Exclusion Based on Age: Distribution justified scientifically • Men will be specifically targeted with several recruitment strategies. Children will not be included as they typically do not bear responsibility for grocery shopping. No upper age limit is included.

Vertebrate Animals
Not Applicable (No Vertebrate Animals) Overall Impact: This R21 project goal is to test a set of text message interventions to improve the healthfulness of grocery store purchases among 64 consumers with low adherence to cancer prevention dietary patterns. They will use a factorial design to test four interventions and examine their feasibility, acceptability, and effect on food purchases and dietary intake; they also aim to quantify the effect of each intervention component on purchases, using store data, and intake, using 24-hour recall. The long-term goal is to optimize these interventions in preparation for full scale trial. This is an experience PI and excellent team with a history of collaboration. There are minor weaknesses in significance and approach, but overall, this study has strong potential for impact in an important area and takes advantage of well conceptualized technology integration with behavior change.

Strengths
• The importance of this area of work is justified.
• Prior research and gaps in the field is well articulated.
• The investigators' own experience with a failed behavioral intervention and the follow up understanding they pursued is a notable strength.

Weaknesses
• There are data to suggest that online shopping is increasing dramatically, which is only minimally acknowledged.

Strengths
• This team is well qualified to conduct the research and has a strong history of collaboration.

Strengths
• Information Machine API for store level tracking.
• The factorial design is in this study context is exciting.
• The objective monitoring of purchases isn't new but very appropriate for this study. • Factorial design in this study context.

Weaknesses
• Could the initial 12 participants be in the intervention (n=64) study?
• There is a discrepancy with the planned enrollment, where it notes the 76 people, but then the intervention testing is happening with 64 (for which there is not planned enrollment table) • Only those with smart phones can participate • More information about access to the store data is needed.

Strengths
• Excellent, supportive environments to carry out this project.

Weaknesses
• None noted

Strengths
• The timeline is appropriate.

Weaknesses
• None noted

CRITIQUE 3
Significance: 2 Investigator(s): 2 Innovation: 1 Approach: 2 Environment: 2 Overall Impact: This study will use a factorial design to experimentally test four intervention components and examine their feasibility, acceptability, and effect on food purchases and dietary intake at 3 and 6 months. (Each component is randomly assigned to be activated for 50% of participants.) The four components to be tested are: 1) Location-triggered text notifications: Reminders and recommendations for food purchases are delivered "just-in-time," when arriving at grocery shopping locations, to enhance goal salience. 2) Reflections on the benefits of change: To enhance motivation, content is added to messages to encourage reflection on the anticipated benefits of healthy eating. 3) Coach monitoring: Food purchases are automatically monitored by a coach (through a system that collects item-level store data) who sends personalized post-purchase messages designed to enhance supportive accountability and thus motivation. 4) Household text: Other adults in the household receive messages designed to elicit support for healthy food purchasing and provide another source of supportive accountability. The preliminary aim of the study is to assess feasibility and acceptability of 1 R21 CA252933-01 9 CLHP BUTRYN, M the intervention components. The primary aim of the study is to quantify the effect of each intervention component, individually and in combination, on grocery store food purchases (objectively assessed with store data), and dietary intake (assessed with 24-hour food recalls). Mediation analyses also will be conducted. The investigators propose to develop and test the feasibility of a new mHealth app to influence food purchasing practices. The goal is novel and the conceptual foundation and intervention procedure is innovative. The team is expert in related development activities, but has minimal involvement/expertise in home food purchasing behaviors. Rigor of Prior Research: The investigators reviewed some of the literature on food purchasing behavior and home food environment. They did not identify the strengths and weaknesses of this research, or what holes they will plug with their research.

Strengths
• The investigators proposed a seemingly comprehensive four component approach to influence healthy food purchasing.

Weaknesses
• None noted

Strengths
• Dr. Butryn has experience with several mHealth interventions, but doesn't spell these out in her Biosketch.
• Dr. Forman has substantial experience in the design and evaluation of JITAI interventions.
• Dr. Milliron lists two publications on food purchasing, and is expert in the use of qualitative methods in the design of interventions.
• The team has expertise in most aspects of the proposed research.

Weaknesses
• The PI reports one involvement in research involving food purchasing. It would have been helpful for the PI to have more expertise in food purchasing behavior.
• It is not clear why so many faculty and consultants with overlapping expertise are involved in this R21 project.
• Although Dr. Milliron lists expertise in qualitative research to facilitate the design of interventions, no such qualitative research was proposed.

Strengths
• Innovations in the proposed research includes the conceptual model, the tools used to promote behavior change and the assessment of food purchasing.

Weaknesses
• None noted

Approach:
Strengths 1 R21 CA252933-01 10 CLHP BUTRYN, M • The investigators propose to develop and test the feasibility of a new mHealth app to influence food purchasing practices. The goal is novel and the conceptual foundation and intervention procedure is innovative.
• An interesting theoretical framework undergirds the proposed research.
• Rigor of Prior Research • The investigators reviewed some of the literature on food purchasing behavior and home food environment. They did not identify the strengths and weaknesses of this research, or what holes they will plug with their research.
• Inclusionary criteria specify participants will be 18 years of age or older. Since people this age are likely to be the main home food purchaser, this age makes sense. Alternatively, 18+ years encompasses a broad variety of developmental stages with differing a) food intake patterns, b) likely food purchasing patterns, c) use of media, preference for type of media communications, etc. This was not discussed in the application.

Weaknesses
• The investigators propose extensive statistical analysis plans, but report no power calculations.
• Given the sample size and four factors in the design, the study will be underpowered to test effect individually or in combination, or to assess mediation. There are accepted standards for reporting feasibility studies. These guidelines should be followed. See S Eldridge et al. BMJ 2016, 355:i5239.
• The intervention specifies a 3-hour workshop to learn about dietary guidelines for cancer prevention. This will be a barrier to any approach to scaling up the intervention. Can abbreviated versions be offered on the internet in small pieces?
• It would appear that the location triggered text notifications (LTTN) would be more effective than generic messages if the LTTN were tailored to the participant's usual purchases at a store?
• The Household Text intervention appears to assume that families have another adult in the home, and that the relationship between members is of equality and openness to new information. The home relationship can vary substantially. It is common in Hispanic families for adult males to be the major influence on food purchasing, but the adult female responsible for preparation. It might be helpful for the investigators to employ some family relationship tool assessment baseline with household texts tailored to the relationship.
• The proposed mediating variables will not be validated for use in the proposed circumstances.
No validity data were provided from comparable samples under comparable circumstances.

Strengths
• Drexel University has recently been recognized as a research level university which can support the proposed research.

Weaknesses
• None noted

Protections for Human Subjects
Acceptable Risks and/or Adequate Protections